1. Field of the Invention
The present invention relates to an apparatus for control of exposure of a camera having an automatic exposure bracket mode drive mode (AEB mode) in which a plurality of pictures are taken while changing the exposure value within a predetermined exposure range.
2. Description of Related Art
A single-lens reflex camera having a photometer (brightness measuring device) and a distance meter (object distance measuring device) incorporated therein is known.
In such a single-lens reflex camera, the distance meter detects a distance (object distance) of an object to be photographed to move a focusing lens in accordance with the object distance thus detected, so that the focusing can be effected. On the other hand, the photometer detects the brightness of the object to determine a shutter speed or a diaphragm value in order to control the exposure in accordance with the brightness thus detected.
Generally speaking, such a single-lens reflex camera has various functions so as to respond to photographers' various requirements. These are, for instance, a continuous photographing mode at which a photographer can successively take pictures while a shutter button is pushed down a; programmed mode at which a combination of a shutter speed and a diaphragm value is determined; and a exposure adjustment mode at which an exposure is adjusted, etc. In particular, a camera is also known having an additional function of an AEB mode at which a plurality of frames of a film can be continuously taken with different exposure varies within predetermined exposure range (width).
According to a feature of the present invention, an exposure control apparatus for a camera is provided. The exposure control apparatus includes a photometer for measuring the brightness of an object to be photographed, a photographing mode setting mechanism for setting a desired photographing mode and a drive mode selecting mechanism for selecting a drive mode of a plurality of drive modes. Further, the exposure control apparatus according to the present invention includes an exposure factor setting device for setting an exposure factor, a film sensitivity setting device for setting the sensitivity of a film and a photometer switch for actuating the photometer.
A release switch is provided for starting a releasing operation. The exposure control apparatus of the present invention further includes an exposure operating mechanism for arithmetically calculating exposure to obtain exposure control factors, based upon the brightness detected by the photometer, the film sensitivity set by the film sensitivity setting device, the exposure factor set by the exposure factor setting device and the drive mode selected by the drive mode selecting mechanism. A photographing control mechanism is provided for performing photographing in accordance with the mode set by the photographing mode setting mechanism and the exposure control factors obtained by the exposure operating device.
According to a significant feature of the present invention, the drive modes include an auto-exposure bracket mode (AEB mode), which can be selected by the drive mode selecting mechansim and the photographing control mechanism and is operative to stop photographing when the release switch is turned OFF during photographing in the AEB mode, photographing being commenced by the releasing operation of the release switch after photographing is stopped at a time when the release switch is turned OFF, so that when the release operation is commenced again by the release switch, photographing in the AEB mode is continued.
Additionally, the photographing control mechanism of the present invention includes a mechanism for associating a time interval between sequential photographing operations within the AEB mode with actuations of the release switch.
According to a further feature of the present invention, the exposure control apparatus operates such that when the release switch is turned OFF during photographing in the AEB mode, photographing being commenced by the releasing operation of this release switch, the photographing control mechanism interrupts the remaining photographing at the AEB mode after the photographing is stopped when the release switch is turned OFF. Further, when the photometer switch is turned OFF, the photographing control mechanism interrupts photographing at the AEB mode upon the lapse of a predetermined period of time after the stop of the operation of the photometer switch.